For Rusty Wagner, the difference between 2012 and 2014 is night and day.

In 2012, Wagner was still a dealer, running a Buick-GMC store in Belleville, Ill., and feeling weighed down by financial challenges, government regulations and fights with General Motors. "It just wasn't fun anymore," said Wagner, who won his franchise back in arbitration after landing on GM's termination list in 2009.

Fast forward two years. He still spends his days at the store, which had been in his family for four generations. But now he works for former competitor Brad Joseph.

"Am I happy? I'm so happy that I don't have the pressures of worrying about a dealership anymore. I have the best of both worlds," said Wagner, who turns 65 in June. "I'm finishing out my auto career and sell the products I loved for all these years, and I get to see customers, but I don't have the worry.

"If Brad has a set of wheels stolen off a car overnight, I feel sorry for him, but I don't have to worry about filling out the insurance claims."

Wagner is among a growing number of dealers selling their stores because of the ever-increasing pressures of running a modern-day dealership. The headaches of expanding government regulations, stricter manufacturer requirements and more demanding Internet-driven competition have many dealers feeling the not-fun blues. Dealership advisers call it one of the leading reasons behind owners' decisions to sell.

Bob Morris, an adviser with Tim Lamb Group, says dissatisfaction is part of many sales he handles.

"It used to be a laugh a minute, and today it's not," said Morris, a dealer himself until 2003. "I hear that constantly. The money is great, but it's not fun anymore. It's just a job."

In January 2013, he sold to Joseph.

Several of the 30 deals that broker Jason Stopnitzky's firm did last year involved dealers who opted to sell because the job no longer held any joy.

For many, the business has become too "sophisticated" in customer relationship management, Internet price transparency, facility requirements and other capital investments, says Stopnitzky of Performance Brokerage Services in Irvine, Calif.

Stuart Lasser sees the same frustration he once felt in nearly every dealer he advises about selling. Lasser was a dealer for 33 years until selling his last store in late 2011. He lost three Saturn stores when GM killed the brand.

Lasser still had Kia and Subaru stores but felt the Internet had fundamentally changed the business. Success required more sophisticated processes. Lasser realized he had to get more serious about the Internet and put better systems in place to close deals. But that wasn't where his interest or skills lay.

"I just couldn't adjust to the retail environment and where it was going. And that's why I chose to get out," said Lasser, now 68. "The day I got out, quite frankly, I woke up the next day and said, 'Wow, I have no employees, I have no government regulations, I have no manufacturer telling me what to spend money on, and it took my money off the table.'"